A machine to machine (M2M, Machine to Machine) technology is integration of wireless communication and information technology, is used for two-way communication, and applies to fields such as security monitoring and detection, vending machines, and cargo tracking. According to a communication object, M2M may be divided to three communication modes: machine to machine, machine to mobile terminal (such as remote user monitoring), and mobile terminal to machine (such as remote user control). In M2M communication, an M2M device accessing a network is also called a machine type communication (MTC, Machine Type Communication) device.
Generally speaking, in a system supporting the M2M communication, the quantity of MTC devices is huge. If each MTC device is authenticated directly according to an authentication method in the prior art, there is a large quantity of signaling interaction in an authentication process between each MTC device and a network side. This kind of signaling traffic generated when a large quantity of MTC devices access a network and perform authentication is not ignorable to the network side. In addition, a large quantity of authentication processes consume a processing capability of the network side. These all bring a heavy load to the network.